Routing Problems 1

[escheider]

Hello:

I have a Cisco 1605r router with 2 ethernet interfaces and 1 serial. The serial interface was preconfigured with a public ip address and is working fine (I can telnet into it from home).

I have assigned a private ip to ethernet 0 and have brought up the interface. I've also enabled ip routing to route between the networks.

From a machine on the same network, I can ping both the serial interface and ethernet 0, however, I cannot get out to the internet. Any help would be great.

Thanks

Eric

 

[donnie00]

Check on Cisco's web site for NAT (Network Address Translation).

 

[escheider]

I've already configured ethernet 0 as ip nat inside. I'll be glad to post running config if needed.

 

[xlee]

Did you create a NAT pool? Post running config would be fine.
Check this site for info:

http://www.cisco.com/warp/public/556/12.html

 

[escheider]

ok, so it looks like I have to create the pool. Since I only have 1 valid ip address, it should look something like this?

ip nat pool nameofpool address1 address2 prefix 24

Where address1 and address2 should be the same address as my external interface?

Also, do I need to configure the serial interface with ip nat outside?

 

[escheider]

Here is Running Config

Current configuration:
!
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Router
!
enable secret xxxx
!
ip subnet-zero
ip name-server 216.248.16.6
!
!
!
interface Ethernet0
ip address 10.102.1.1 255.255.255.0
ip broadcast-address 10.102.1.255
no ip directed-broadcast
ip nat inside
!
interface Ethernet1
ip address 10.101.1.1 255.255.255.0
no ip directed-broadcast
shutdown
!
interface Serial0
ip address 216.x.x.x 255.255.255.252
no ip directed-broadcast
encapsulation ppp
service-module t1 timeslots 1-24
!
ip classless
ip route 0.0.0.0 0.0.0.0 216.248.5.189
!
!
line con 0
password xxxx
transport input none
line vty 0 4
password xxxx
login
!
end

 

[marsd]

example:
int s0
ip nat outside
int eth0
ip nat inside

ip nat pool homez-nat $s0address $s0address prefix-length 24
!translated external address
access-list 20 permit $private_net $netmask
!allowed inside host range
ip nat inside source list 20 pool homez-nat overload
!configured nat translation for PAT.

troubleshoot with sh ip nat translations.

Good Luck.

 

[escheider]

would the prefix-length be 24 or 30? I have a 30 bit public ip address

 

[marsd]

30 it is..sold!

 

[eracer919]

Private IP space is not publicly routable, therefore once your packet leaves your outside interface it will get dropped by the ISP/ next hop router. You will need to setup NAT(network address translation) on your router. This will traslate your private address to your public address. Packets will then flow. Make sure you are using a valid public DNS server for name resolution as well

 

[wybnormal]

LOL- eracer-- dont believe everything you read ;-) for example, I had to renumber my own LAN from 192.168.1.x due to the fact that part Pacbell's network was bleeding over into my range.. I did a DSN audit of my range and about 100 nodes from their network showed up all with 192.168.1.x numbering. when I would runa trace route, my first hop was their router which kicked it back to mine.. instead of trying to figure it all out, I just renumbered and firewalled my network. I did send them an email suggestion to close the hole, whatever it is/was.. no response

MikeS Find me at

http://www.packetattack.com

"Diplomacy; the art of saying 'nice doggie' till you can find a rock" Wynn Catlin